Interactive view-driven evenly spaced streamline placement

This paper presents an Interactive View-Driven Evenly Spaced Streamline placement algorithm (IVDESS) for 3D explorative visualization of large complex planar or curved surface flows. IVDESS rapidly performs accurate streamline integration in 3D physical space, i.e., the flow field, while achieving high quality streamline density control in 2D view space, i.e., the output image. The correspondence between the two spaces is established by using a projection-unprojection pair constituted through geometric surface rendering. An inter-frame physical-space seeding strategy based on streamline reuse+lengthening is adopted, on top of intra-frame view-space seeding, to not only enable coherent flow navigation but also speedup placement generation. IVDESS employs a view-sensitive streamline representation that is well suited for streamline reuse, lengthening, and rendering. In addition, it avoids temporal incoherence caused by streamline splitting and jaggy lines caused by unprojection errors. Our algorithm can run at interactive frame rates (9FPS for placement generation) to allow for 3D exploration of surface flows with smooth evolution of high-density (1%) evenly spaced streamlines in a large window (990 x 700 pixels) on an ordinary PC without either pre-processing or GPU support.